Brake



C. PRESS July 15,1941.

BRAKE Filed Feb. 27, 1957 v6 sheets-Sheet l STVv vll 7 @Il f III INVENTOR` Cr-HQL Dreess 4Q. 074 ATTORNEY. l

July 15, 1941. 3.r PRESS BRAkE Filed Feb. 27. 1937 6 Sheets-Sheet 3 iwf@ S mp wm E O VL n m@ a C Vi 8%/ July 15, 1941.

c.. PRI-:ss 2,249,227

BRAKE Filed Feb. 27, 1937 6 SheetsSheet 4 C "warg-ron l @QL @E55 268 BY C. PRESS l July l5, 1941.

v BRAKE Filed Feb. 27, 1937 6 Sheets-Sheet 5 u@ R Y.. oE .E D. N Mp @R E O mL n n im m PRESS nA July 15', 1941.

BRAKE Filed Feb. 27. 1937 6 Sheets-Sheet 6 J INVENTR. By (ljwress ATTORNEY.

irl/lll; A

Patented July 15', 1.941

BRAKE Carl Press, South Bend, Ind., asslgnor to Bendix Products Corporation, South Bend, 1nd., a corporation of Indiana Application February 27, 1937, Serial No. 128,104 3 Claims. (Cl. Gil-54.5)

This invention relates to brakes and is illustrated as a hydraulic brake system.

One of the objects of this invention is toprovidea hydraulic brake system so arranged that the brakes may be applied in 'a conventional manner and without any substantial losses of pedal travel in all ordinary cases, but so arrangedthat in case of breakage or failure of any single part, at least some of the brakes may be applied notwithstanding the breakage.

A further objectof the invention is to provide improved simple means for bleeding such a system and improved simple means for compensating the various portions of the system.

One feature of my invention is the provision of a master cylinder formed with the conventional bore in which the operating piston moves and with a bore connected thereto and provided with pistons to separate the various sections of the hydraulic system from the operating bore.

A further feature of the invention is the provision of a bleeding bore which is normally connected individually to the separated sections and is arranged to be connected upon the withdrawal of a bleed screw with the operating bore.

A further feature of the invention is the provision of a reservoir which is connected by means of compensating ports not only with the operating'bore but also with the separated sections.

Further objects and' features of the invention will be apparent after a reading of the subjoined specication and claims and after consideration 'of Figure 2; y

Figure 5 is a fragmentary sectional view taken throughs. portion of the cylinder substantially as if on the line 5-5 oi Figure 2;

Figure is a sectional view corresponding to a portion oi' Figure 3 but showing a diiferentform of master cylinder;

Figure 7 is a sectional view corresponding toy Figure 3 and showing a still further modification;

Figure-8 is a fragmentary sectional view corresponding to the rearward portion of Figure 2 but showing the master cylinder of Figure 7, and taken substantially on the line 8-8 of Figure 7;

Figure 9 is a fragmentary sectional view taken through a portion of the cylinder substantially as if on the line 9--9 of Figure 7;

Figure 10 is a sectional view corresponding to Figure 2 and showing a still further modification;

Figure 11 is a fragmentary sectional view taken through a portion of the cylinder substantiall as if on the line II-II of Figure l0; f

Figure 12 is a fragmentary sectional view taken through a portion of the cylinder substantially as if on the line I2-l2 of Figure 10;

Figure 13 is a fragmentary sectional view corresponding to a portion of Figure 3 and showing a still further modification;

Figure 14 is a fragmentary sectional view corresponding to Figure 13 and showing a still further modiflcation; A

Figure 15 is a view similar to Figure 1 showing the system incorporating the modification shown in Figure 6; l

Figure 16 is a view similar lto Figure 2 showing the modification of Figure 6;

Figure .17 is a view similar to Figure 5 taken substantially on the line II-I'l of Figure 16; and

Figure 18 isa view substantially similar to Figure 4 taken on the line iB-IB of Figure 16.

Referring in detail to the drawings, it may be seen that I have shown in'Figure 1 diagrammatir cally a portion of the supporting gear of an automobile together with a hydraulic brake system therefor. .There are provided four wheels l0 each equipped with a wheel brake I2 whichis arranged to be actuated by wheel cylinder I4. To each of these wheel cylinders iluid may be delivered by' conduits i8, Il, 20, 22, 24 and 28. A pedal 2l is arranged to actuate a master cylinder 30 vto .force fluid through the conduits to the wheel brake cylinders. The master cylinder 30 is shown more in detail in Figures 2 to 5 inclusive and.

comprises an operating bore 32 in which there is arranged an operating piston 'I4 operated bya piston rod 36 which is in turn connected to the foot pedal 28. Ports are formed in the wall oi' the bore 32 designated as ports 38 and 40. 'I'hese ports are connected toA a reservoir I2 which is also connected as by passages 4l and I6 with reservoirs 4I and 50. The bore 32 is connected as by an opening l! with a cross bore 5t' arranged T-shaped in a laterally extending rearward extension .of the master cylinder, the lateral exof 100 as are used in Figures 2 to 5 inclusive.

tension being'aesignatea ss. Positioned 1n the bore 54 are provided a pair oi? pistons 53'which are arranged to separate the -fiuid in the main operating bore of the cylinder from the fluid in the ends of the cross bore 54. From the ends of the cross bore the iiuid may be delivered through the ports 55 and 52 to the conduits 22 and 25 respectively.

In Figure 2 the operating piston is shown in its released position and thus it may be seen that the piston 34 is positioned so that the port 45 leading to the reservoir is uncovered. Similarly in Figures 3 and 4 the pistons 53 are shown in their released positions so that 4(Figure 4) the compensating ports 54 are uncovered. Between the pistons 55 there is provided a pin 53 which serves as a stop to limit the inner position of the pistons 55, the said pistons being 'normally returned to contact with said pin by springs 55. A spring is provided similarly for returning the piston 34 to its released position.l 'I'he pistons 53 are provided with grooves 12 with which spring pressed pins 14 are arranged to coact to serve as latches-for holding the pistons 53 in their outermost position in the eventthat the pistons are ever forced to that outermost position. Thus in the event of failure or leak in either the front brakes or the rear brakes the corresponding piston 55 will be forced outward to its outermost limit and will be held there by the spring pressed pins 14 so that on subsequent strokes there will be no loss of pedal travel in applying the remaining brakes. By reason of the ports 34 and the port 43 all portions of the system are normally connected in the released position of the pistons with the reservoir 42. Thus all portions of the system may be compensated vfor variations in volume of the iiuid due to changes of the temperature.

Means are provided for filling the system with iiuid in the bleeding operation. As shown in Figures 2, 3 and5 there is provided in the lateral section 55 a small cross bore 13 which is connected by means of inclined bores 15 with the portions of the system beyond the pistons 53.` A plug 15 normally closes oif a passageway 3l connected with the bore 32 and normally separates the two cylinder is shown, the modiiication being designated 230 and the parts being designated by the same numerals as are used in Figures 2 to 5 inclusive with the addition of 200. The extension 255 is, however, formed with a pair of bores 254`and 255 arranged -parallel to each other and with their axesf parallelto the extended axis of the main cylinder instead of at right angles thereto. The bleed bore 215 extends generally rearward and upward and intersects at its rearward end a right angle bore 213 connected with the bores 254 and 25,5. The intersection between' the bores 215 and 213 is closed except during the bleeding` operation by a bleeding screw 215.

In the embodiment shown in Figure 10, the master cylinder proper is designated by the nu- 'meral 335 andis of the Aconventional type. The

various elements are designated by the same nul merals as those used in Figures 2 to 5. inclusive with the addition of -300. Anattachment. or

` auxiliary cylinder 33| is formed separately from the main cylinder 33|| and is arranged to besecured thereto having a boss 38| screwed intothe rear end of the cylinder 330 as at 350. The auxiliary cylinder 33| is provided withl two separate auxiliary reservoirs 343. It has a pair of bores 354 and 355 with pistons 353 in said bores. It is provided with intersecting bores 313 and 313 controlled by a bleed screw 315.

In the arrangement shown in Figurel 13, the auxiliary cylinder 44| has pistons 455 with which there are associated latch pins 414. The threaded boss 43| by which the cylinder 44| is threaded into the main cylinder 433 is also threaded internally as at 432 to receive a hollow pin 434. The pin 434 serves not only to allow liquid to pass from the main cylinder 435 into theauxiliary cylinder 44| butalso serves to position the return ends of the bore 13 from each other. Thus when the plug 13 is screwed in the position shown in Figure 5 for normal operation of the brakes the portions of the system beyond the pistons 53 are in effect separated from each other and from the operating bore 32. However, the plug 15 may be unscrewed to a certain extent for bleeding so that the passages are all connected and allI parts of the system are connected with each other. Thereupon the system may be filled with liquid in the usual manner by operation of the piston 34.

In Figure 6 there is shown a modication of the mastercylinder in which there are provided separated lines for each of the four wheel brakes. Figure 6 corresponds generally to Figure 3 and the same numerals are used with the addition It will be noted, however, that the cylinder `|3|| shown in Figure 6 has a lateral section |53 which is provided with two auxiliary bores, one designated |54 and the other designatedV |55. The bore |54 has outlets |35 and |52 and the bore |55 has outlets |5| and |53. Additional pistons |53 are provided for bore |55 andan additional stop pin |55 is also provided for the bore |55. An additional small-bore |11 controlled by bleeder screws |13 is also associated with the bore 55.

In Figures 7, 8 and 9 another modied form of of the pistons 453.

In Figure l4`, I have shown an auxiliary cylinder 54| provided with pistons 553, the pistons' being each formed intermediate their ends with a reduced portion 533 and with a groove in said reduced portion designated as 512. Pins 533 are formed with recesses 551 in which there are inserted latch pins 514. Thus the'pins 555 limit the inward movement ofthe pistons 553 and the latches 514 are arranged to hold the pistons in o their outward positions in event of a break.y

In the operation of the various forms of my invention, when released all portions'of the systems are connected to the reservoirs. However, when the pistons 34 are moved forward to apply the brakes the ports -43 are cuto ff and pressure acting on the rear of the pistons 53 move those pistons forward to cut oil the ports 54. Fluid ahead of these pistons is forced out through the conduits to apply the brakes. Should a wheel cylinder leak or a conduit break, the piston 53 associated with that portion of the system moves forward until the associated latch -pin 14 locks in the groove 12, holding the piston forward. Thereafter thesystem is again nlled as soon as the piston 34 goes back to its released position and lfuture operations'of the pedal operate only the other portion of the system. In bleeding the screw'15 is removed and the portions of the system being interconnected the by-passing around the pistons-53, theusual bleed l ports. in the wheel cylinders I4 may be opened inthe usual manner, and all air removed from the system and the system entirely lled with liquid from -the reservoir 42 by repeated depression of the pedal 28, the piston- 34 acting asia pump to force the liquidfrom the reservoir into the system;

It is to be understood that the above-described embodiments of my invention are for the purpose of illustration .only and various changes may be made therein without departing from the spirit and scope of the invention.

I claim: I

1. A hydraulic brake system comprising a plurality of wheel brakes, motor cylinders for each of ,said wheel brakes for applying them, separated conduits 'for conveying', uid under vpressure to said motor cylinders, a master cylinder for creating pressure in the fluid used, a reservoir normally connected to the master cylinder, connections by Which uid pressure is transferred from said master cylinder to said separate conduits, and means in said connections for separating the fluid in said master cylinder from the uid in said conduits, said means comprising pistons formed with a groove and latches associated with said pistons, a main bore in which said pistons move, and means for limiting the return'posidv Yin a bore formed from the reservoir to themain bore.

2. A hydraulic brake system comprising a plurality of wheel brakes, motor cylinders for each of said wheel brakes for applying them, separated in said master cylinder from the fluid in said conduits, a reservoir for supplying fluid 'to said` master cylindercand at timesto said separated conduits, and means for limiting the return position of said pistons comprising a pin positioned in a bore leading from the reservoir to the main bore. i

3. A hydraulic brake system comprising a plurality of wheel brakes, motor cylinders for each of said wheel brakes for applying them, separated conduits for conveying iiuid pressure to said motor cylinders, a master cylinder for creating pressure in the fluid used, connections by which uid pressure is transferred from said master cylinder to said separate conduits, means in said connections comprising pistons and a main bore in which said pistons move for separating the fluid in said master cylinder from the fluid in said conduits, a reservoir for supplying uid to said master cylinder and` at times to said separated conduits, means for limiting the return position of said pistons comprising a pin positioned in a bore leading from the reservoir to the main f bore, a passageby which vsaid reservoir may be 

